α-Fe_(2)O_(3)/epoxy resin composite superhydrophobic coating was prepared withα-Fe_(2)O_(3) nanoparticles and epoxy resin by spin coating method.The coating without epoxy resin has higher contact angle(CA)and lower ...α-Fe_(2)O_(3)/epoxy resin composite superhydrophobic coating was prepared withα-Fe_(2)O_(3) nanoparticles and epoxy resin by spin coating method.The coating without epoxy resin has higher contact angle(CA)and lower ice adhesion strength(IAS),but the mechanical properties are poor.Theα-Fe_(2)O_(3)/epoxy resin composite superhydrophobic coating exhibits good mechanical durability.In addition,compared with the bare aluminum substrate,the Ecorr of the composite coating is positive and the Jcorr is lower.The inhibition efficiency of the composite coating is as high as 99.98%in 3.5 wt%NaCl solution.The difference in the microstructure caused by the two preparation methods leads to the changes in mechanical properties and corrosion resistance of composite superhydrophobic coating.展开更多
The icing of transmission lines threatens the security of power system. This paper proposes a novel anti-icing method based on reducing voltage of the transmission lines. The line voltage can be reduced by regulating ...The icing of transmission lines threatens the security of power system. This paper proposes a novel anti-icing method based on reducing voltage of the transmission lines. The line voltage can be reduced by regulating the ratio of the transformers which install the both ends of the transmission lines. The line current can be increased and the power loss of the transmission lines can also be increased, which means the heat generated by power loss increases and the icing process of the transmission lines can be restrained. When the icing may occur in the atrocious weather, the anti-icing transformers installed the both ends of transmission line are put into operation. The ratios of transformers are regulated to the appropriate value. The current of transmission line can be increased to the value that is a little greater than the critical current, which can realize the purpose of anti-icing. At the same time, the conditions of normal running in the load side are kept invariably, which can ensure the security of power system. This method can be applicable to a wide range. It's an effective measure to prevent the icing of the transmission lines.展开更多
In this work,the super-hydrophobic(SH)surface was prepared through chemical vapor deposition process by an argon atmospheric pressure plasma jet source with HMDSN(hexamethyldisilazane)as the polymerization precursor.P...In this work,the super-hydrophobic(SH)surface was prepared through chemical vapor deposition process by an argon atmospheric pressure plasma jet source with HMDSN(hexamethyldisilazane)as the polymerization precursor.Plasma synthesized organosilicon(SiOxCyHz)thin films with water contact angle over 160°and sliding angle below 5°,were able to be achieved.FTIR and XPS analysis indicates a large number of hydrocarbon compositions were polymerized in the thin films enduing the latter very-low surface free energy.SEM shows the SH films display micro-nanostructure and with high degree of averaged surface roughness 190 nm evaluated by AFM analysis.From experiments under controlled low-temperature and moisture conditions,the prepared SH surface exhibits good anti-icing effects.Significantly prolonging freezing time was achievable on the SH thin films for both static and sliding water droplets.This investigation demonstrates the anti-icing potentials of SH surface prepared through low-cost simple atmospheric-pressure plasma polymerization process.展开更多
Many flight and icing conditions should be considered in order to design an efficient ice protection system to prevent ice accretion on the aircraft surface. The anti-icing heat load is the basic knowledge for the des...Many flight and icing conditions should be considered in order to design an efficient ice protection system to prevent ice accretion on the aircraft surface. The anti-icing heat load is the basic knowledge for the design of a thermal anti-icing system. In order to help the design of the thermal anti-icing system and save the design time, a fast and efficiency method for prediction the anti-icing heat load is investigated. The computation fluid dynamics (CFD) solver and the Messinger model are applied to obtain the snapshots. Examples for the calculation of the anti-icing heat load using the proper orthogonal decomposition (POD) method are presented and compared with the CFD simulation results. It is shown that the heat loads predicted by POD method are in agreement with the CFD computation results. Moreover, it is obviously to see that the POD method is time-saving and can meet the requirement of real-time prediction.展开更多
An anti-icing surface has been designed and prepared with an aluminum panel by creating an artificial lotus leaf which is highly hydrophobic. The hydrophobicity of a solid surface can be generated by decreasing its su...An anti-icing surface has been designed and prepared with an aluminum panel by creating an artificial lotus leaf which is highly hydrophobic. The hydrophobicity of a solid surface can be generated by decreasing its surface tension and increasing the roughness of the surface. On a highly hydrophobic surface, water has a high contact angle and it can easily rolls off, carrying surface dirt and debris with it. Super-cooled water or freezing rain can also run off this highly hydrophobic surface instead of forming ice on the surface, due to the reduction of the liquid-solid adhesion. This property can also help a surface to get rid of the ice after the water becomes frozen. In this study, a Cassie-Baxter rough surface was modeled, and an aluminum panel was physically and chemically modified based on the modeled structure. Good agreement was found between predicted values and experimental results for the contact and roll-off angles of water. Most importantly, by creating this highly hydrophobic aluminum rough surface, the anti-icing and de-icing properties of the modified surface were drastically improved compared to the control aluminum surface, and the cost will be reduced.展开更多
As a passive anti-icing strategy,properly designed superhydrophobic coatings can demonstrate outstanding performances.However,common preparation strategies for superhydrophobic coatings often lead to environmental pol...As a passive anti-icing strategy,properly designed superhydrophobic coatings can demonstrate outstanding performances.However,common preparation strategies for superhydrophobic coatings often lead to environmental pollution,high energy-consumption,high-cost and other undesirable issues.Besides,the durability of superhydrophobic coating also plagues its commercial application.In this paper,we introduced a facile and environment-friendly technique for fabricating abrasion-resistant superhydrophobic surfaces using thermoplastic polyurethane(TPU)and modified SiO_(2)particles(SH-SiO_(2)).Both materials are non-toxicity,low-cost,and commercial available.Our methodology has the following advantages:use of minimal amounts of formulation,take the most streamlined technical route,and no waste material.These advantages make it attractive for industrial applications,and its usage sustainability can be promised.In this study,the mechanical stability of the superhydrophobic surface was evaluated by linear wear test.It is found that the excellent wear resistance of the superhydrophobic coating benefits from the characteristics of raw materials,the preparation strategy,and the special structure.In anti-icing properties test,the TPU/SH-SiO_(2)coating exhibits the repellency to the cold droplets and the ability to extend the freezing time.The electrochemical corrosion measurement shows that the asprepared superhydrophobic surface has excellent corrosion resistance that can provide effective protection for the bare Q235 substrates.These results indicate that the TPU/SH-SiO_(2)coating possesses good abrasion resistance and has great potential in anti-corrosion and anti-icing applications.展开更多
It has been proved that the construction of interconnected armour on superhydrophobic surface could significantly enhance the mechanical robustness.Here,a new kind of armour with frame/protrusion hybrid structure was ...It has been proved that the construction of interconnected armour on superhydrophobic surface could significantly enhance the mechanical robustness.Here,a new kind of armour with frame/protrusion hybrid structure was achieved by nanosecond laser technology.Then,this armoured superhydrophobic surface demonstrated excellent durability,which could withstand linear abrasion(~3 N press)800 cycles,water jet test(1.0 MPa pressure)40 times and 100℃treatment 18 days.Particularly,the armoured superhydrophobic sample shows outstanding anti-icing ability,which can speed up the supercooled water dropping(no adhesion within 2 h),increase the freezing delay time by~3 times and maintain low adhesion force(less than 35 kPa)after 30 icing/de-icing cycles.Further finite element analysis and theoretical modeling proved that the developed frame/protuberance hybrid structure could effectively enhance the durability.The relatively low surface accuracy in this study can significantly reduce processing cost,which provides a bright future for the practical application of armour superhydrophobic materials.展开更多
While superhydrophobic coatings have shown promise as potential anti-icing coatings, the surface roughness of these coatings is prone to damage during repeated icing-deicing cycles. Herein, two kinds of superhydrophob...While superhydrophobic coatings have shown promise as potential anti-icing coatings, the surface roughness of these coatings is prone to damage during repeated icing-deicing cycles. Herein, two kinds of superhydrophobic anti-icing coatings are prepared from organic resin and micro-nano particles using two strategies, and their excellent anti-icing properties are also investigated. However, superhydrophobic surface Ⅰ(SF1), prepared by first strategy, cannot be used for extended periods of time due to irreversible damage to the surface roughness during the icing–deicing process. Finite element simulations and experimental studies are preformed to investigate the fatal issue of such roughness damage. In contrast,the anti-icing properties of superhydrophobic surface Ⅱ(SF2), prepared by second strategy, can easily regain through a simple sandpaper abrasion treatment even the surface roughness was damaged during the icing–deicing process. These exploratory results and SF2 preparation strategy provide a facile design of anti-icing coating, and the derived restorable anti-icing coating is expected to be useful for a wide application.展开更多
Ice accretion on surfaces of the aircraft and engine is a serious threat to the flight safety.In this paper,a novel hot air anti-icing method is proposed based on the porous foam.Taking the NACA0012 airfoil as an exam...Ice accretion on surfaces of the aircraft and engine is a serious threat to the flight safety.In this paper,a novel hot air anti-icing method is proposed based on the porous foam.Taking the NACA0012 airfoil as an example,the traditional thermal protection structure is proved to exist the deficiency in balancing the heat exchange caused by route loss of the heat.By dividing the hot chamber into multiple regions to fill with various foam metal,flow resistance characteristics and heat transfer characteristics for this protection mode are analyzed in order to derive the maximized benefit in anti-icing process.The calculation results reveal that,under the same condition,the region filled with foamed copper not only improves the temperature uniformity on the anti-icing area,but also achieves a better protection effect for enhancing heat transfer between the tube and the hot gas,averagely above 20℃higher than it without porous foam filling in surface temperature.Additionally,the minimum mass flow rate of the protection hot air is reduced by 16.7%.The gratifying efficiency of the porous filler in fortifying heat transfer confirms the potential of replacing the efficient but complex heat transfer design with simple structure filled with foam metal.展开更多
Although superhydrophobic materials have attracted much research interest in anti-icing,some controversy still exists.In this research,we report a cost-effective method used to verify the contribution of area fraction...Although superhydrophobic materials have attracted much research interest in anti-icing,some controversy still exists.In this research,we report a cost-effective method used to verify the contribution of area fraction to ice adhesion strength.We tried to partially-embed siliea nanopnarticles into microscale fabrics of a commercial polyamide mesh.Then,the area fraction could be determined by altering the mesh size.Generally,the ice adhesion strength decreases as the area fraction decreases.An ice adhesion strength of~1.9 kPa and a delayed freezing time of~1048 s can be obtained.We attribute the low ice adhesion strength to the combination of superhydro-phobicity and stress concentration.The superhydrophobicity prohibits the water from penetrating into the voids of the meshes,and the small actual contact area leads to stress concentration which promotes interfacial crack propagation.Moreover,our superhydrophobic mesh simultaneously exhibis a micro-nano hierarchical structure and a partally-cmbedded structure.Therefore,the as-prepared superhydrophobic mesh retained the ieephobicity after 20 icingldeicing cycles,and maintained its superhydrophobicity even afier 60 sandpaper-abrasion cycles and a 220"C thermal treatment.展开更多
This paper introduces an effective anti-icing strategy that uses passive anti-icing property and active de-icing functions concurrently.These dual capabilities can alleviate the icing problem more effectively than eit...This paper introduces an effective anti-icing strategy that uses passive anti-icing property and active de-icing functions concurrently.These dual capabilities can alleviate the icing problem more effectively than either a passive or active function alone.The developed material is a slippery liquid-repellent elastic conductor(SLEC);it is an organogel that is composed of multi-walled carbon nanotubes,oil,and polydimethylsiloxane.The SLEC maintains passive water-droplet sliding ability even on wet surfaces that frequently occur in cold conditions(e.g.,during condensation and defrosting),suppresses ice nucleation,and shows ice adhesion strength as low as^20 kPa.The SLEC releases heat when it is subject to electrical or photonic stimulation,and can therefore it can prevent ice formation and melt ice that has already formed on a surface.This material has sustainable liquid repellence by syneresis and replenishment;this ability ensures long-lasting anti-icing property,and results in exceptional durability.This durability is stable against mechanical damage.The superior dual anti-icing capabilities together with the sustainable and stable liquid repellence should generate synergistic effects,and yield a powerful anti-icing tool that can broaden the range of icing applications.展开更多
With the help of double hydrogen bonds between urea groups, a self-healing anti-icing coating was prepared from polydimethylsiloxane(PDMS)-based polyurea(PDMSPU) that was synthesized from bis(3-aminopropyl)-terminated...With the help of double hydrogen bonds between urea groups, a self-healing anti-icing coating was prepared from polydimethylsiloxane(PDMS)-based polyurea(PDMSPU) that was synthesized from bis(3-aminopropyl)-terminated PDMS and2,4-toluene diisocyanate. Furthermore, by incorporating a lubricant of inert silicone oil and the cross-linking agent of 1,3,5-tris-(4-aminophenoxy)benzene(TAPOB), the anti-icing coatings exhibited elastic, slippery and durable properties. The wettability,ice shear strength, abrasion-resistance, mechanical and self-healing properties of the prepared anti-icing coatings were systematically investigated. Results showed that the ice shear strength of the PDMSPU anti-icing coating with 150 wt% silicone oil was 7.9±2.9 kPa, significantly lower than that of pristine PDMSPU(74.7±7.2 kPa). The additional introduction of 2 wt%TAPOB could effectively counteract the adverse effect of the lubricant so that the tensile strength(~1 MPa) of the coating could be comparable to pristine PDMSPU(855±96 kPa). The PDMSPU coating containing 150 wt% silicone oil and 2 wt% TAPOB could maintain the ice shear strength below 50 kPa against 10 icing/deicing cycles and at 12.0±3.3 kPa after 5000 abrasion cycles, and exhibit self-healing properties after treating at 60°C for 10 or 15 h. The slippery self-healing PDMSPU anti-icing coatings could be suitable for anti-icing surfaces in low temperature environments.展开更多
As a century-old concept,superwettability has aroused the interest of researchers in the past decades,attributed to the discoveries of the mechanisms of special wetting phenomena in nature.Bio-inspired manufacturing o...As a century-old concept,superwettability has aroused the interest of researchers in the past decades,attributed to the discoveries of the mechanisms of special wetting phenomena in nature.Bio-inspired manufacturing of superwetting surfaces for fog collection and anti-icing applications has become mainstream research,potentially alleviating the problem of water shortage and ice accidents.Superwetting surfaces for fog collection and anti-icing applications involve a reverse process,in which the former gathers water spontaneously,while the latter repels water.Contrastive analysis of the two is essential for the comprehensive understanding of superhydrophilic/superhydrophobic surfaces and boosting their applications.Herein,wetting theories and basic mechanisms for fog collection and anti-icing are briefly introduced.Then,manufacturing methods of bionic structures and surfaces are systematically reviewed after discussing the typical organisms with superwettability.Finally,conclusions are drawn and prospects for future development are proposed.展开更多
The harsh working environment affects the performance and usage life of Al and its alloys,thus limiting their application.In recent years,Slippery Liquid-infused Porous Surface(SLIPS)has attracted much attention due t...The harsh working environment affects the performance and usage life of Al and its alloys,thus limiting their application.In recent years,Slippery Liquid-infused Porous Surface(SLIPS)has attracted much attention due to excellent anti-corrosion,anti-fouling and anti-icing properties.This may be an effective way to improve the properties of Al and its alloys.Here,the SLIPS with petal-like structure was constructed on the Al alloy via simple hydrothermal reaction,Stearic Acid(STA)modification and lubricant injection.A variety of droplets(including oil-in-water emulsions)can slide on the SLIPS at a low angle,even the Sliding Angle(SA)of the water droplet is only 3°.Furthermore,the SLIPS exhibits outstanding mechanical and chemical properties.It can maintain fine oil-locking ability under high shearing force and keep slippery stability after immersion in acid/alkaline solutions.In addition,the SLIPS possesses excellent anti-corrosion,anti-fouling and anti-icing properties,which provides a new way to promote the application of Al and its alloys.Therefore,the SLIPS is expected to be an effective way to improve the properties of Al and its alloys,as well as play a role in anti-fouling and self-cleaning in construction,shipbuilding and automotive manufacturing industries,thereby expanding the practical application of Al and its alloys.展开更多
The multiple jets impingement heat transfer is widely applied in the wing anti-icing system.It is challenging to apply the similarity criterion to carry out the anti-icing experiments due to the complex flow and heat ...The multiple jets impingement heat transfer is widely applied in the wing anti-icing system.It is challenging to apply the similarity criterion to carry out the anti-icing experiments due to the complex flow and heat transfer behavior.In the present study,the full-scale slat model is used to carry out anti-icing experimental researches in a 2 m×3 m icing wind tunnel of China Aerodynamics Research and Development Center.The effects of icing parameters Liquid Water Content(LWC)and Median Volume Diameter(MVD)and hot air parameters(mass flow rate and temperature)on the thermal performance of an inner-liner anti-icing system with jets impingement heat transfer are studied.The effects of the experimental parameters are analyzed in detail by combining impingement and evaporation heat transfer mechanisms.The impingement hot air mass flow rate dramatically affects the heat transfer performance of the impingement stagnation region within the range of the experimental parameters.The temperature of impingement hot air and that of wing skin are approximately linear correlated.The experimental results show the effects of LWC and MVD on water film formation and runback ice accretion.The formation of water film is analyzed by an analytical method based on the wing skin temperature difference of dry and wet air conditions.展开更多
Superior anti-icing and active deicing multifunctional surfaces are highly desired in outdoor infrastructure and work of aircraft,automobiles,wind turbines,power transmission,etc.Herein,inspired by microstructures and...Superior anti-icing and active deicing multifunctional surfaces are highly desired in outdoor infrastructure and work of aircraft,automobiles,wind turbines,power transmission,etc.Herein,inspired by microstructures and functions of natural opal and Nepenthes pitcher plants,we present a novel multifunctional inverse opal slippery anti-icing surface(IOSAS)by employing a combined method of colloidal nanoparticles self-assembly,microstructure mold replication,and hydrophobic lubricating fluid infiltration.Because of the 3D long range ordered nanoscale porous structure of artificial inverse opal,the lubricating liquid could wick into,wet,and stably adhere to IOSAS,forming thousands of solid-liquid interfaces and defect-free and inert slippery surface.Thus,the IOSAS was imparted with inhibiting ice nucleation property and hindering heat transfer and ice crystals’growth characteristics.Owing to the existence of a thin liquid layer on the surface,the mechanical interlock between porous substrate and ice is greatly weakened,which imparts the slippery surface with low ice adhesion strength,and the frozen droplet and ice bulk could be easily removed.In addition,we have demonstrated that the supercooled IOSAS has no adhesion to moving water droplets,while various subcooled metal surfaces are adhesive,and this exhibits liquid-infused inverse opal surfaces dynamic low-temperature water-repellent performance.These characteristics endow IOSAS with multifunctional anti-icing performances,making it a promising option for a wide range of ice-phobic applications.展开更多
Ice-nucleating proteins(INPs)are the most effective ice-nucleating agents that play a significant role in preventing freeze injuries in freeze-tolerant organisms.INPs promote ice nucleation in the extracellular space,...Ice-nucleating proteins(INPs)are the most effective ice-nucleating agents that play a significant role in preventing freeze injuries in freeze-tolerant organisms.INPs promote ice nucleation in the extracellular space,harvesting water from cells due to the low vapor pressure of ice compared with water,thereby protecting freeze-tolerant organisms from intracellular freezing.The antifreeze mechanism of INPs offers a unique opportunity to inhibit large-scale freezing by localized control of ice formation,with valuable enlightenment in anti-icing material sciences.By learning from nature,we transferred the excellent ice nucleation-facilitating capability of INPs along with an antifreeze concept of spatially controlled ice nucleation to anti-icing material design,fabricating icephobic coatings that consisted of patterned hydrogel-encapsulated INP(PHINP).The ice patterns were templated by patterned PHINPs via the tuning of ice nucleation so that the ice coverage fraction could be controlled by<30%on almost all PHINP-coated surfaces.Combining PHINP with solar-thermal conversion surfaces endowed the composite coatings with high anti-icing performances at any time of the day.展开更多
基金Supported by the National Natural Science Foundation of China(No.51801058)the Special Program for Guiding Local Science and Technology Development by the Central Government of Hubei Province(No.2019ZYYD006)the Education and Teaching Research Project of Hubei Polytechnic University(No.2021B01)。
文摘α-Fe_(2)O_(3)/epoxy resin composite superhydrophobic coating was prepared withα-Fe_(2)O_(3) nanoparticles and epoxy resin by spin coating method.The coating without epoxy resin has higher contact angle(CA)and lower ice adhesion strength(IAS),but the mechanical properties are poor.Theα-Fe_(2)O_(3)/epoxy resin composite superhydrophobic coating exhibits good mechanical durability.In addition,compared with the bare aluminum substrate,the Ecorr of the composite coating is positive and the Jcorr is lower.The inhibition efficiency of the composite coating is as high as 99.98%in 3.5 wt%NaCl solution.The difference in the microstructure caused by the two preparation methods leads to the changes in mechanical properties and corrosion resistance of composite superhydrophobic coating.
文摘The icing of transmission lines threatens the security of power system. This paper proposes a novel anti-icing method based on reducing voltage of the transmission lines. The line voltage can be reduced by regulating the ratio of the transformers which install the both ends of the transmission lines. The line current can be increased and the power loss of the transmission lines can also be increased, which means the heat generated by power loss increases and the icing process of the transmission lines can be restrained. When the icing may occur in the atrocious weather, the anti-icing transformers installed the both ends of transmission line are put into operation. The ratios of transformers are regulated to the appropriate value. The current of transmission line can be increased to the value that is a little greater than the critical current, which can realize the purpose of anti-icing. At the same time, the conditions of normal running in the load side are kept invariably, which can ensure the security of power system. This method can be applicable to a wide range. It's an effective measure to prevent the icing of the transmission lines.
基金partly supported by the State Key Laboratory of Advanced Electromagnetic Engineering and Technology(No.AEET 2018KF003)National Natural Science Foundation of China(Nos.51637002,11405144)+3 种基金the Fundamental Research Funds for the Central Universities(Nos.2018CDXYTW0031,20720150022)the Construction Committee of Chongqing(No.2018-1-3-6)the International Science&Technology Cooperation Program of China(No.2015DFR70390)the Natural Science Foundation of Hunan Province(No.2018JJ3587)
文摘In this work,the super-hydrophobic(SH)surface was prepared through chemical vapor deposition process by an argon atmospheric pressure plasma jet source with HMDSN(hexamethyldisilazane)as the polymerization precursor.Plasma synthesized organosilicon(SiOxCyHz)thin films with water contact angle over 160°and sliding angle below 5°,were able to be achieved.FTIR and XPS analysis indicates a large number of hydrocarbon compositions were polymerized in the thin films enduing the latter very-low surface free energy.SEM shows the SH films display micro-nanostructure and with high degree of averaged surface roughness 190 nm evaluated by AFM analysis.From experiments under controlled low-temperature and moisture conditions,the prepared SH surface exhibits good anti-icing effects.Significantly prolonging freezing time was achievable on the SH thin films for both static and sliding water droplets.This investigation demonstrates the anti-icing potentials of SH surface prepared through low-cost simple atmospheric-pressure plasma polymerization process.
文摘Many flight and icing conditions should be considered in order to design an efficient ice protection system to prevent ice accretion on the aircraft surface. The anti-icing heat load is the basic knowledge for the design of a thermal anti-icing system. In order to help the design of the thermal anti-icing system and save the design time, a fast and efficiency method for prediction the anti-icing heat load is investigated. The computation fluid dynamics (CFD) solver and the Messinger model are applied to obtain the snapshots. Examples for the calculation of the anti-icing heat load using the proper orthogonal decomposition (POD) method are presented and compared with the CFD simulation results. It is shown that the heat loads predicted by POD method are in agreement with the CFD computation results. Moreover, it is obviously to see that the POD method is time-saving and can meet the requirement of real-time prediction.
文摘An anti-icing surface has been designed and prepared with an aluminum panel by creating an artificial lotus leaf which is highly hydrophobic. The hydrophobicity of a solid surface can be generated by decreasing its surface tension and increasing the roughness of the surface. On a highly hydrophobic surface, water has a high contact angle and it can easily rolls off, carrying surface dirt and debris with it. Super-cooled water or freezing rain can also run off this highly hydrophobic surface instead of forming ice on the surface, due to the reduction of the liquid-solid adhesion. This property can also help a surface to get rid of the ice after the water becomes frozen. In this study, a Cassie-Baxter rough surface was modeled, and an aluminum panel was physically and chemically modified based on the modeled structure. Good agreement was found between predicted values and experimental results for the contact and roll-off angles of water. Most importantly, by creating this highly hydrophobic aluminum rough surface, the anti-icing and de-icing properties of the modified surface were drastically improved compared to the control aluminum surface, and the cost will be reduced.
基金Financial support from the National Natural Science Foundation of China(No.21676216)Special project of Shaanxi Provincial Education Department,China(20JC034)+1 种基金Basic research program of Natural Science in Shaanxi Province,China(2019JLP-03)Innovation project of college students in Shaanxi Province,China(S202010697054)are gratefully acknowledged.
文摘As a passive anti-icing strategy,properly designed superhydrophobic coatings can demonstrate outstanding performances.However,common preparation strategies for superhydrophobic coatings often lead to environmental pollution,high energy-consumption,high-cost and other undesirable issues.Besides,the durability of superhydrophobic coating also plagues its commercial application.In this paper,we introduced a facile and environment-friendly technique for fabricating abrasion-resistant superhydrophobic surfaces using thermoplastic polyurethane(TPU)and modified SiO_(2)particles(SH-SiO_(2)).Both materials are non-toxicity,low-cost,and commercial available.Our methodology has the following advantages:use of minimal amounts of formulation,take the most streamlined technical route,and no waste material.These advantages make it attractive for industrial applications,and its usage sustainability can be promised.In this study,the mechanical stability of the superhydrophobic surface was evaluated by linear wear test.It is found that the excellent wear resistance of the superhydrophobic coating benefits from the characteristics of raw materials,the preparation strategy,and the special structure.In anti-icing properties test,the TPU/SH-SiO_(2)coating exhibits the repellency to the cold droplets and the ability to extend the freezing time.The electrochemical corrosion measurement shows that the asprepared superhydrophobic surface has excellent corrosion resistance that can provide effective protection for the bare Q235 substrates.These results indicate that the TPU/SH-SiO_(2)coating possesses good abrasion resistance and has great potential in anti-corrosion and anti-icing applications.
基金supported by Beijing Nature Science Foundation(3232054)National Nature Science Foundation of China(51977079)+4 种基金Key Laboratory of Icing and Anti/De-icing of CARDC(Grant No.IADL 20210401)the Central Guidance on Local Science and Technology Development Fund of Hebei Province(226Z1204G)the Top Young Innovative Talents of Colleges and Universities of Higher Learning Institutions of Hebei(BJ2021095)Youth Elite Scientists Sponsorship Program by Chinese Society for Electrical Engineering(CSEE-YESS-2017002)the Fundamental Research Funds for the Central Universities(2020MS115).
文摘It has been proved that the construction of interconnected armour on superhydrophobic surface could significantly enhance the mechanical robustness.Here,a new kind of armour with frame/protrusion hybrid structure was achieved by nanosecond laser technology.Then,this armoured superhydrophobic surface demonstrated excellent durability,which could withstand linear abrasion(~3 N press)800 cycles,water jet test(1.0 MPa pressure)40 times and 100℃treatment 18 days.Particularly,the armoured superhydrophobic sample shows outstanding anti-icing ability,which can speed up the supercooled water dropping(no adhesion within 2 h),increase the freezing delay time by~3 times and maintain low adhesion force(less than 35 kPa)after 30 icing/de-icing cycles.Further finite element analysis and theoretical modeling proved that the developed frame/protuberance hybrid structure could effectively enhance the durability.The relatively low surface accuracy in this study can significantly reduce processing cost,which provides a bright future for the practical application of armour superhydrophobic materials.
基金supported by the National Natural Science Foundation of China(No.32171693)the Fundamental Research Funds for the Central Universities(No.2572021CG02)the Fundamental Research Funds for the Central Universities(No.2572017AB16).
文摘While superhydrophobic coatings have shown promise as potential anti-icing coatings, the surface roughness of these coatings is prone to damage during repeated icing-deicing cycles. Herein, two kinds of superhydrophobic anti-icing coatings are prepared from organic resin and micro-nano particles using two strategies, and their excellent anti-icing properties are also investigated. However, superhydrophobic surface Ⅰ(SF1), prepared by first strategy, cannot be used for extended periods of time due to irreversible damage to the surface roughness during the icing–deicing process. Finite element simulations and experimental studies are preformed to investigate the fatal issue of such roughness damage. In contrast,the anti-icing properties of superhydrophobic surface Ⅱ(SF2), prepared by second strategy, can easily regain through a simple sandpaper abrasion treatment even the surface roughness was damaged during the icing–deicing process. These exploratory results and SF2 preparation strategy provide a facile design of anti-icing coating, and the derived restorable anti-icing coating is expected to be useful for a wide application.
文摘Ice accretion on surfaces of the aircraft and engine is a serious threat to the flight safety.In this paper,a novel hot air anti-icing method is proposed based on the porous foam.Taking the NACA0012 airfoil as an example,the traditional thermal protection structure is proved to exist the deficiency in balancing the heat exchange caused by route loss of the heat.By dividing the hot chamber into multiple regions to fill with various foam metal,flow resistance characteristics and heat transfer characteristics for this protection mode are analyzed in order to derive the maximized benefit in anti-icing process.The calculation results reveal that,under the same condition,the region filled with foamed copper not only improves the temperature uniformity on the anti-icing area,but also achieves a better protection effect for enhancing heat transfer between the tube and the hot gas,averagely above 20℃higher than it without porous foam filling in surface temperature.Additionally,the minimum mass flow rate of the protection hot air is reduced by 16.7%.The gratifying efficiency of the porous filler in fortifying heat transfer confirms the potential of replacing the efficient but complex heat transfer design with simple structure filled with foam metal.
基金supported by National Nature Science Foundation of China(51977079,51607067)Youth Elite Scientists Sponsorship Program by Chinese Society for Electrical Engineering(CSEE-YESS-2017002)the Fundamental Research Funds for the Central Universities(2020MS115,2017MS149).
文摘Although superhydrophobic materials have attracted much research interest in anti-icing,some controversy still exists.In this research,we report a cost-effective method used to verify the contribution of area fraction to ice adhesion strength.We tried to partially-embed siliea nanopnarticles into microscale fabrics of a commercial polyamide mesh.Then,the area fraction could be determined by altering the mesh size.Generally,the ice adhesion strength decreases as the area fraction decreases.An ice adhesion strength of~1.9 kPa and a delayed freezing time of~1048 s can be obtained.We attribute the low ice adhesion strength to the combination of superhydro-phobicity and stress concentration.The superhydrophobicity prohibits the water from penetrating into the voids of the meshes,and the small actual contact area leads to stress concentration which promotes interfacial crack propagation.Moreover,our superhydrophobic mesh simultaneously exhibis a micro-nano hierarchical structure and a partally-cmbedded structure.Therefore,the as-prepared superhydrophobic mesh retained the ieephobicity after 20 icingldeicing cycles,and maintained its superhydrophobicity even afier 60 sandpaper-abrasion cycles and a 220"C thermal treatment.
文摘This paper introduces an effective anti-icing strategy that uses passive anti-icing property and active de-icing functions concurrently.These dual capabilities can alleviate the icing problem more effectively than either a passive or active function alone.The developed material is a slippery liquid-repellent elastic conductor(SLEC);it is an organogel that is composed of multi-walled carbon nanotubes,oil,and polydimethylsiloxane.The SLEC maintains passive water-droplet sliding ability even on wet surfaces that frequently occur in cold conditions(e.g.,during condensation and defrosting),suppresses ice nucleation,and shows ice adhesion strength as low as^20 kPa.The SLEC releases heat when it is subject to electrical or photonic stimulation,and can therefore it can prevent ice formation and melt ice that has already formed on a surface.This material has sustainable liquid repellence by syneresis and replenishment;this ability ensures long-lasting anti-icing property,and results in exceptional durability.This durability is stable against mechanical damage.The superior dual anti-icing capabilities together with the sustainable and stable liquid repellence should generate synergistic effects,and yield a powerful anti-icing tool that can broaden the range of icing applications.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51603143 and 51273146)the Natural Science Foundation of Tianjin, China (Grant Nos. 18JCQNJC03800 and 14ZCZDGX00008)。
文摘With the help of double hydrogen bonds between urea groups, a self-healing anti-icing coating was prepared from polydimethylsiloxane(PDMS)-based polyurea(PDMSPU) that was synthesized from bis(3-aminopropyl)-terminated PDMS and2,4-toluene diisocyanate. Furthermore, by incorporating a lubricant of inert silicone oil and the cross-linking agent of 1,3,5-tris-(4-aminophenoxy)benzene(TAPOB), the anti-icing coatings exhibited elastic, slippery and durable properties. The wettability,ice shear strength, abrasion-resistance, mechanical and self-healing properties of the prepared anti-icing coatings were systematically investigated. Results showed that the ice shear strength of the PDMSPU anti-icing coating with 150 wt% silicone oil was 7.9±2.9 kPa, significantly lower than that of pristine PDMSPU(74.7±7.2 kPa). The additional introduction of 2 wt%TAPOB could effectively counteract the adverse effect of the lubricant so that the tensile strength(~1 MPa) of the coating could be comparable to pristine PDMSPU(855±96 kPa). The PDMSPU coating containing 150 wt% silicone oil and 2 wt% TAPOB could maintain the ice shear strength below 50 kPa against 10 icing/deicing cycles and at 12.0±3.3 kPa after 5000 abrasion cycles, and exhibit self-healing properties after treating at 60°C for 10 or 15 h. The slippery self-healing PDMSPU anti-icing coatings could be suitable for anti-icing surfaces in low temperature environments.
基金supported by the National Natural Science Foundation of China(Grant Nos.51222508 and 51175210)。
文摘As a century-old concept,superwettability has aroused the interest of researchers in the past decades,attributed to the discoveries of the mechanisms of special wetting phenomena in nature.Bio-inspired manufacturing of superwetting surfaces for fog collection and anti-icing applications has become mainstream research,potentially alleviating the problem of water shortage and ice accidents.Superwetting surfaces for fog collection and anti-icing applications involve a reverse process,in which the former gathers water spontaneously,while the latter repels water.Contrastive analysis of the two is essential for the comprehensive understanding of superhydrophilic/superhydrophobic surfaces and boosting their applications.Herein,wetting theories and basic mechanisms for fog collection and anti-icing are briefly introduced.Then,manufacturing methods of bionic structures and surfaces are systematically reviewed after discussing the typical organisms with superwettability.Finally,conclusions are drawn and prospects for future development are proposed.
基金supported by the National Natural Science Foundation of China(no.51735013 and 51905520)the Pre‐Research Program in National 14th Five‐Year Plan(grant number 61409230614).
文摘The harsh working environment affects the performance and usage life of Al and its alloys,thus limiting their application.In recent years,Slippery Liquid-infused Porous Surface(SLIPS)has attracted much attention due to excellent anti-corrosion,anti-fouling and anti-icing properties.This may be an effective way to improve the properties of Al and its alloys.Here,the SLIPS with petal-like structure was constructed on the Al alloy via simple hydrothermal reaction,Stearic Acid(STA)modification and lubricant injection.A variety of droplets(including oil-in-water emulsions)can slide on the SLIPS at a low angle,even the Sliding Angle(SA)of the water droplet is only 3°.Furthermore,the SLIPS exhibits outstanding mechanical and chemical properties.It can maintain fine oil-locking ability under high shearing force and keep slippery stability after immersion in acid/alkaline solutions.In addition,the SLIPS possesses excellent anti-corrosion,anti-fouling and anti-icing properties,which provides a new way to promote the application of Al and its alloys.Therefore,the SLIPS is expected to be an effective way to improve the properties of Al and its alloys,as well as play a role in anti-fouling and self-cleaning in construction,shipbuilding and automotive manufacturing industries,thereby expanding the practical application of Al and its alloys.
基金co-supported by the National Numerical Wind Tunnel Project(No.NNW2018-ZT2B04)the “973”Program of China(No.2015CB755800)。
文摘The multiple jets impingement heat transfer is widely applied in the wing anti-icing system.It is challenging to apply the similarity criterion to carry out the anti-icing experiments due to the complex flow and heat transfer behavior.In the present study,the full-scale slat model is used to carry out anti-icing experimental researches in a 2 m×3 m icing wind tunnel of China Aerodynamics Research and Development Center.The effects of icing parameters Liquid Water Content(LWC)and Median Volume Diameter(MVD)and hot air parameters(mass flow rate and temperature)on the thermal performance of an inner-liner anti-icing system with jets impingement heat transfer are studied.The effects of the experimental parameters are analyzed in detail by combining impingement and evaporation heat transfer mechanisms.The impingement hot air mass flow rate dramatically affects the heat transfer performance of the impingement stagnation region within the range of the experimental parameters.The temperature of impingement hot air and that of wing skin are approximately linear correlated.The experimental results show the effects of LWC and MVD on water film formation and runback ice accretion.The formation of water film is analyzed by an analytical method based on the wing skin temperature difference of dry and wet air conditions.
基金supported by the National Natural Science Foundation of China(Grant Nos.51725602 and 52036006)the Scientific Research Foundation of Graduate School of Southeast University(Grant No.YBPY 2113).
文摘Superior anti-icing and active deicing multifunctional surfaces are highly desired in outdoor infrastructure and work of aircraft,automobiles,wind turbines,power transmission,etc.Herein,inspired by microstructures and functions of natural opal and Nepenthes pitcher plants,we present a novel multifunctional inverse opal slippery anti-icing surface(IOSAS)by employing a combined method of colloidal nanoparticles self-assembly,microstructure mold replication,and hydrophobic lubricating fluid infiltration.Because of the 3D long range ordered nanoscale porous structure of artificial inverse opal,the lubricating liquid could wick into,wet,and stably adhere to IOSAS,forming thousands of solid-liquid interfaces and defect-free and inert slippery surface.Thus,the IOSAS was imparted with inhibiting ice nucleation property and hindering heat transfer and ice crystals’growth characteristics.Owing to the existence of a thin liquid layer on the surface,the mechanical interlock between porous substrate and ice is greatly weakened,which imparts the slippery surface with low ice adhesion strength,and the frozen droplet and ice bulk could be easily removed.In addition,we have demonstrated that the supercooled IOSAS has no adhesion to moving water droplets,while various subcooled metal surfaces are adhesive,and this exhibits liquid-infused inverse opal surfaces dynamic low-temperature water-repellent performance.These characteristics endow IOSAS with multifunctional anti-icing performances,making it a promising option for a wide range of ice-phobic applications.
基金The authors gratefully acknowledge the financial support from The National Key Research and Development Program of China(grant no.2020YFE0100300)Chinese National Nature Science Foundation(grant nos.51925307,21733010,21875261,and 21805286)+2 种基金National Key R&D Program of China(grant no.2018YFA0208502)Key Research Program of Frontier Sciences,CAS(grant no.ZDBS-LYSLH031)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(grant no.2018044).
文摘Ice-nucleating proteins(INPs)are the most effective ice-nucleating agents that play a significant role in preventing freeze injuries in freeze-tolerant organisms.INPs promote ice nucleation in the extracellular space,harvesting water from cells due to the low vapor pressure of ice compared with water,thereby protecting freeze-tolerant organisms from intracellular freezing.The antifreeze mechanism of INPs offers a unique opportunity to inhibit large-scale freezing by localized control of ice formation,with valuable enlightenment in anti-icing material sciences.By learning from nature,we transferred the excellent ice nucleation-facilitating capability of INPs along with an antifreeze concept of spatially controlled ice nucleation to anti-icing material design,fabricating icephobic coatings that consisted of patterned hydrogel-encapsulated INP(PHINP).The ice patterns were templated by patterned PHINPs via the tuning of ice nucleation so that the ice coverage fraction could be controlled by<30%on almost all PHINP-coated surfaces.Combining PHINP with solar-thermal conversion surfaces endowed the composite coatings with high anti-icing performances at any time of the day.
